1. Field of the Invention
The present invention relates to a display device driver that drives a display device in response to a video signal.
2. Background Art
In display devices such as liquid crystal displays, pixels are formed at crossing parts between a plurality of scanning lines extending in a horizontal direction on a two-dimensional screen and a plurality of signal lines extending in a vertical direction on the two-dimensional screen. Such a display panel incorporates a signal driver that applies voltages, which correspond to the luminance levels of pixels each indicated by video data, to the respective signal lines. The display panel also incorporates a scanning driver that applies scanning voltages to the respective scanning lines in sequence.
As a display apparatus that incorporates such drivers, there is proposed an apparatus configured to divide a plurality of pieces of video data for one horizontal period into groups and to shift voltage application timing of the video data groups in units of video data groups. With this configuration, the apparatus avoids the situation where steep change in currents simultaneously occurs in signal line groups and thereby prevents noise generated in such a situation (see, for example, Japanese Patent Application Laid-Open No. 2010-39061).
As the size of the display panel increases, interconnection resistance of the scanning lines extending in the horizontal direction on the two-dimensional screen increases in particular. As a result, scanning signals on the scanning lines have a larger delay amount due to the interconnection resistance as they are more distant from the scanning driver. Therefore, when voltages (hereinafter referred to as pixel drive voltages) corresponding to the luminance levels slowly rise on the signal lines, voltage values of the pixel drive voltages, defined in the respective pixels while the scanning voltages are applied, are higher in the pixels placed at positions (on the scanning lines) where the delay amount of the scanning signals is larger. This causes so-called display unevenness, that is, variations in display luminance depending on pixel positions.